commit aeffbf33603a6f58f20a532f4a2c8df0a2371ed4
author Robin Thellend <rthellend@google.com> Sat Apr 09 20:39:07 2016 -0700
committer Robin Thellend <rthellend@google.com> Sat Apr 09 20:39:07 2016 -0700
tree b637118d501b29bf40915566dbfb9a8d75f292a0
parent a7f99e390fe4d02c9284caf7cdba3a697e65640b

runtime: Fail when GCE metadata is inaccessible

When V23_EXPECT_GOOGLE_COMPUTE_ENGINE is set and non-empty, the runtime
will fail to initialize when the GCE metadata server is inaccessible or
some of its data cannot be retrieved.

When V23_EXPECT_GOOGLE_COMPUTE_ENGINE is not set (or is empty), the
previous behavior is preserved, i.e. we give up after 1 second and
assume we're not on GCE.

Production services cannot function properly when the metadata isn't
there. It's better to abort immediately than to keep running in a bad
state.

While at it, clean up the code around cloud VM metadata.

Fixes https://github.com/vanadium/issues/issues/1267

Change-Id: I933f97179b994c83460b2efe6658c8f098689531